I may be wrong on this, but here's the question. I think somewhere along the line I got the idea that when a particular chambering is developed it is designed around or with a certain weight or design of bullet in mind. Is this true?

As an example, and I may be wrong, but I believe that the 270 Win was designed with a 130 gr bullet in mind and that weight is "ideal" for the cartridge. Am I correct in this? And what I'm curious about, if correct, what bullet weight or design was the 25-06 Remington and the 260 Remington designed around.

Dave

Rifleman---

It's always been my opinion that the 270 Winchester gained an excellent reputation for a big game rifle because it was a unique bore diameter and all the bullets of that diameter were made for THAT cartridge and the velocities for which it was designed. That remained true until the 270 Weatherby came out and IMMEDIATELY there were stories about failures to penetrate and lost game.

The 25-06 was brought out with a 1-10 twist which is best with 100 to 120 gr. bullets.

I don't know about the .260. I've never messed with one and probably won't.

140gr is the ideal for the 260!

Kimmo

Matching the length of the bullet to the twist rate, freebore and case capacity will probably do more for good terminal performance than fretting about the weight. The diameters of the bore and groove dictate the diameter of the bullet and, similarly, the twist rate will require an optimum bullet length. Anything much longer or shorter than the ideal is simply second best.

Yes, I agree that the .270 was really built around the 130 grain bullet and that combination made it an excellent longrange performer on medium game and without heavy recoil.

Hey rifleman, I believe the concept you are searching for was long ago refered to as "The Natural Bullet Weight".

The real interesting part concerning it is that two people having the same caliber(a 270Win in your example) may select two different weights as "The Natural Bullet Weight".

The reason for this is because it requires the shooter analize and balance the various performance factors of each bullet weight, assign priorities to their relative value(to him) and then see which weight meets his specific needs the best.

For example, someone may select the "flattest trajectory" possible and "least recoil" as their #1 and #2 priorities. Using your 270Win they may decide to go with a 100gr BarnesX for The Natural Bullet Weight.

Another guy may want "highest retained energy" with the "deepest penetration" at 200yds and go with a 160gr Nosler Partition as his "Natural Bullet Weight".

Any parameter concerning the flight of the bullet that is of importance to you needs to be considered by looking in the External Ballistic Tables in the back of your Speer Manual. Other factors such as recoil, powder consumption, effect of unique bullet construction, etc. are fair game to toss in the balancing act too.

So, it is really up to the individual Shooter to select The Natural Bullet Weight for his particular Game and hunting environment.

Best of luck to you.

[ 01-17-2003, 04:16: Message edited by: Hot Core ]

Thanks for the replies.

Jack, yes you hit on a key point mentioning rate of twist, as that is a huge key when talking about bullet weight and design for a particular rifle & caliber.

Gina, I tried to convey weight and design part in my question but kinda failed there, which is partly what you were referring to when you mentioned length.

Kimmo, thanks for the comment on the 260, does that come from your experience with the 260 or reading or....? I would have guessed somewhere in the 120 to 130 gr bullets, but that's why I asked the question.

Leo, thanks also, I also beleive I read somewhere in the past that (in theory) the 165 gr bullet is generally the goto bullet weight for the 30-06.

When I use the words IN THEORY, thats huge because we all know that rifle to rifle there is no one IDEAL bullet weight that will always work, but is there a best place to start, is where I'm coming from.

Dave

and here I was, thinking Sd would have something to do with it....

IMHO

for rifles (not pistols
under .200 is a varmit bullet
.250 is a perfect SD for north american game
.300 and higher is SURE penetration, assuming a good bullet.

Which means,
.277 130gr, .242 SD
.264 120 .246
.308 168 .253 (perfect)
.358 225 .250
.375 300 .305
.416 400 .330
.458 400 .272 (see, it's NOT a african weight)
.458 500 .341

and, these are the "classic" or near it weights for these guns.
jeffe
and,

The 243 Winchester performs well with the 100 gr bullet and many shoot 70 gr bullets in it for pests. Now some favor 55 gr bullets in that cartridge.

The 30/06 shoots great groups with 125 gr bullets and shoots 200 gr bullets as well.

Seems that you can use almost any reasonable weight bullet to me.

Slightly expanded version of my reply from another forum --

I've thought about this a little -- one clue to this is to look at the bullet drop pics in the Barnes manual and see which weights start to drop more dramatically at long ranges due to the "velocity gap." Usually there's a range of bullet weights that are pretty darn close to each other, then the heavier ones are down at the bottom of the picture.

E.g. in .30-06 a 180-gr. drops just a few tenths more at 300 than a 165-gr. but a 200 or 220 drops off a lot faster. But in .300 H&H or .300 Win. Mag., the 200 is almost as flat as a 180. Not coincidentally, you will find very few people who think a quality 180-gr. bullet like the Partition is a bad choice for the .30-06, same for the 200-gr. in the .300 mags.

There's also the issue of what velocity the bullets are designed to handle, which with conventional bullets tends to favor the middle range with velocities around 2500-2900 fps, e.g. 150-200 gr. for the .30-06 with 165s and 180s again in the sensible middle ground. At higher velocities you start needing extra-special bullets and at lower velocities you may need to make sure your bullets are soft enough for consistent expansion. So one aspect of "ideal" weight is the weight at which normal bullets will work for normal hunting.

Just a few fairly conservative thoughts.

John

John Fraser,

Your concerns seem plasable but the facts show that all the bullets do well.

The following data is all from Nosler #5 for the 30/06 using maximum loads for Nosler Partitions out of the same barrel.

The first number is a 150gr, second the 180 and last a 200 gr.

First velocity at 300 yards: 2324-2231-2156 fps. No concerns here. I think 2100 fps is plenty to expand.

Now energy: 1766-1990-2064 again no big difference with a slight edge to the longer bullets.

Now drop at 300 yards with a 200 yd zero and 1.5" scope height: -6.88", -7.19, -8.45 again not much change and only about an inch more drop between the 180 and the 200 gr. That's hard to see at 300 yards!

Last wind drift: 7.4"-6.5"-6.8" No difference here.

The only real difference is that the bigger bullets are suitable for bigger game if of the same construction.

The opposite argument is easier to sell. That there is no standard weight for a given caliber. And the availability of modern bullets are driving this home.

[ 01-18-2003, 07:06: Message edited by: Savage99 ]

I agree that twist rate and the task at hand has more to do with it than anything. Consider the 8X57. It began with something near a 200 grn bullet (196??), then it was very widley and succesfully used with a 150. Nowadays many consider the 170 grn to be the "optimum weight". How about the 7mm RM? Its a sweet shooter with a number of different sizes..

I submit that it is a fine thing to have any number of weights available for a given cartridge. Use what works for you.

Gentlemen, the optimum bullet weight and type per caliber is truly which ever bullet the rifle likes the best. An example is my 308's I have one that I shoot the 155 Plama bullet in, and I had another one built with the idea of shooting the 175 Sierra MK in it. Try as I might I could not get that bullet to shoot the way I wanted it to. So I tried the Palma bullet and it loved it. So I tried the 175 MK in the other one. It shot the 175 as well as it did the Palma. I just swapped which rilfe I was going to shoot them in. Let the rilfe tell you. The rifle won't lie!

Shoot Safe, Shoot Straight......RiverRat

RiverRat,
You will find that your two rifles have differing twist rates and that the one that does not like the 175gr bullet is slower than the other.